If you have been following a while you know I am not a huge fan of “Blanket Advisories/Watches/Warnings”. What they are is wide scale area and or time period covered by unspecific information. Yesterday afternoon I chose not to post a Winter Storm Watch (WSW) issued in the afternoon because it had wording covering Steamboat to Hesperus. Not all of the information can apply to all of the areas listed and it is confusing. If you asked them why they do that they would say they just need to raise awareness early about the upcoming event. I get that, it is the right thing to do, it does not make it less confusing. I figured they would clean it up overnight, which they did by geographic location, but not by timeframe. I don’t know if they will revise it any further, if necessary they will likely just add areas. There is still so much uncertainty on the Thursday night event (as well as some even for tonight) that it is possible we won’t know have much of an idea what will happen until Thursday afternoon before it starts, not as it starts. What we will be hoping for is a dry start measured by dewpoint. If the air is dry enough it will allow for adiabatic cooling which will lower snow levels. If the dewpoints are too high this top-down cooling cannot take place and most of us will be in for a rain slush event changing to snow right before the system departs. Above 8,500′ wet heavy snow should fall.
Here is the WSW, later today, I am going to look at the events separately to hopefully get a better-detailed outlook for you.
NORTHWEST SAN JUAN MOUNTAINS-SOUTHWEST SAN JUAN MOUNTAINS-
INCLUDING THE CITIES OF TELLURIDE, OURAY, LAKE CITY, SILVERTON,
RICO, AND HESPERUS
314 AM MST WED FEB 13 2019
…WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO
NOON MST FRIDAY…
* WHAT…SNOW EXPECTED. TOTAL SNOW ACCUMULATIONS OF 6 TO 12 INCHES
EXPECTED WITH LOCAL AMOUNTS UP TO 16 INCHES. WINDS GUSTING AS
HIGH AS 40 MPH.
* WHERE…NORTHWEST SAN JUAN MOUNTAINS AND SOUTHWEST SAN JUAN
* WHEN…FROM 5 PM THIS AFTERNOON TO NOON MST FRIDAY.
* ADDITIONAL DETAILS…TRAVEL COULD BE VERY DIFFICULT TO
IMPOSSIBLE ABOVE 8000 FEET. PATCHY BLOWING SNOW COULD
SIGNIFICANTLY REDUCE VISIBILITY. THE HEAVIEST SNOW IS EXPECTED
TO FALL TONIGHT WITH A SECOND ROUND OF HEAVY SNOW ARRIVING LATE
THURSDAY AFTERNOON AND EVENING.
I’ll be back, probably around noon.